]]>It’s fairly obvious what many people think of the giant sport utes that roam the roads like the mastodons and woolly mammoths of another age: They’re too wide. They’re too tall. They drink too much gas.

Yes, it’s easy to condemn big sport-utility vehicles, but the fact is, a lot of folks actually need them – those who tow boats or horse trailers, those who carry six or seven kids to baseball or soccer games and those who load up lots of gear for weekend family outings; their numbers total around three-quarters of a million people. For these consumers, owning a full-size SUV is more about necessity than vanity.

For critics of big SUVs, if you don’t need to carry all those people or tow a trailer, then get a smaller horse.

To perform the tasks that owners require, there is very little that automakers can do to reduce the size of SUVs. However, the Chevrolet Tahoe Hybrid (and its corporate cousins, the GMC Yukon Hybrid and Cadillac Escalade Hybrid) makes significant strides in improving the fuel economy of the full-size SUV.

When Chevrolet introduced the 2008 Tahoe Hybrid, it was the first vehicle to utilize the advanced two-mode hybrid powertrain developed jointly by General Motors, BMW and the former DaimlerChrysler. The full-size SUV marked the launch of a new breed of larger vehicles that were greener than their gas-powered versions, albeit a light shade of green.

But as one automotive pundit said at the time, “There is a method to GM’s madness … For a Tahoe going from 16 mpg to 21 mpg, driving 15,000 miles a year will save 223 gallons. Going from 30 mpg to 39 mpg only saves 115 gallons annually. Admittedly, the Tahoe still uses a lot more fuel overall, but the savings are impressive nonetheless.”

The numbers work out – drivers who absolutely must have all of that seating, storage and towing capacity are actually doing more to cut their annual fuel consumption by buying a hybrid full-size SUV, than drivers who are upgrading from a standard Toyota Camry to a Camry Hybrid. Even though hybrids like the Tahoe or Yukon and Escalade may not yield their owners 40 mpg, the fuel savings they provide over their gas-guzzling counterparts are undeniable.

Chevrolet has not made any changes to the Tahoe Hybrid’s exterior, interior or powertrain since it was introduced. Available with either two- or four-wheel drive, the 2013 Tahoe Hybrid gets three new exterior colors. The MSRP for the 2WD version is $52,295, a $630 increase over the 2012 model. The 4WD starts at $55,100, also a $630 increase.

Hybrid Powertrain

Most of the fuel economy gains come from the electrically variable transmission (EVT). The transmission is made up of two 60-kilowatt electric motors, three planetary gearsets and four fixed gears that use the same space as GM’s six-speed automatic transmission. Essentially the EVT has two drive modes – hence the name “two-mode hybrid.” In the first mode, during stop-and-go and city drives, the Tahoe can operate with electric power only, gas engine power only or a combination of both. Like Ford and Toyota hybrids, the Tahoe Hybrid shuts the engine off when the vehicle stops, and when its time to go, the electric motors propel the big SUV to around 30 mph for a couple of miles.

In the second mode, the 332 horsepower 6.0-liter V8 engine is the primary source of motivation, and one or both electric motors can run concurrently along with the engine in order to provide a power boost. If the Tahoe is pulling a load, the transmission locks out the electrically variable gears and both electric motors. It shifts over to the four fixed gears, so the V8 is the sole source of power. A computer monitors the entire system and determines every 1/100th of a second what method is the most efficient means to propel the vehicle.

The crux of the Tahoe Hybrid’s powertrain is the V8 engine with cylinder deactivation technology (known at GM as active fuel management). In other words, the engine can shut down four of its eight cylinders when additional power is not needed. Camshaft phasing, and late-intake valve closure allows even more efficient engine operation. Beyond the engine, there’s a 300-volt nickel metal hydride battery pack tucked neatly under the second-row seats.

More Fuel Economy Tricks

The two-mode system is an engineering masterpiece, but with the battery pack, it adds more than 300 pounds to the Tahoe. To compensate – weight is a fuel economy killer – the hood and tailgate are aluminum. The lighter-weight aluminum is used on the wheels, which are low mass, aero-efficient 18-inch forged aluminum.

Improved aerodynamics, another fuel-saving trick, include removing the roof rails, lowering the chassis 10 millimeters, elimination of front tow hooks and fog lights, a deeper air dam below a new front facia and reshaping the running boards. The wheel openings have also been re-sized and in the rear, an extended rear spoiler was added. These exterior tweaks reduced the drag coefficient from 0.36 to 0.34. A final fuel-miser is a set of low-rolling resistance tires.

Exterior And Interior

The Tahoe Hybrid’s truck heritage isn’t hidden; its looks announce that it is definitely an old school, truck-based SUV. The chiseled styling, athletic stance, and handsome 18-inch wheels really give the Tahoe a flair of elegance, while at the same time looking brawny and capable. In front, the twin-port horizontal grille is enhanced by the Hybrid’s aerodynamic changes. From the outside, the Tahoe Hybrid is unmistakably a Chevy, but it’s a Chevy with style, looks that have held up well against the test of time.

Inside, time hasn’t been as kind. The dash and instrument panel now look dated compared to the latest Chevrolet cars and crossovers. Also, the hard plastics and lack of soft surfaces fall behind alternatives from other carmakers.

On the plus side, the Tahoe Hybrid offers a very spacious cabin similar to the standard Tahoe. The seats are a little bit thinner and lighter than in the standard model – another weight adjustment – but no comfort was sacrificed for the swap-out. The SUV offers seating for eight and vast cargo room, whether it be for luggage, groceries, or lumber. The second row of seats shows the biggest deviation from the standard model, having been redesigned to accommodate the hybrid battery pack.

From a driver’s viewpoint, switchgear operates elegantly and lies easily to hand. The tachometer includes an auto stop position to let the driver know when the engine is shut off. In the upper left corner, a gauge indicates the optimal braking range to achieve a regenerative charge for the battery as well as showing drivers if they are driving in the most efficient manner. Below the tachometer, a readout shows instant mileage and V4 mode operation. On the center stack, a graphic can be switched on that shows how the vehicle is operating—electric only, gas only or a combination of both.

Maximum towing capacity of 6,200 pounds for the two-wheel-drive Tahoe Hybrid and 6,000 pounds for the four-wheel-drive version falls short of the conventional Tahoe’s 8,200-pound maximum. If you look at only hybrid SUVs, however, the Tahoe Hybrid and its sibling, the GMC Yukon Hybrid, are far and away the towing leaders that have seating for eight. Volkswagen’s 2013 Touareg Hybrid has a tow rating of 7,700 pounds but it’s a five-passenger SUV and costs nearly $7,000 more.

As a work truck, the Tahoe Hybrid is as tough as any. It is rugged enough to handle the abuses of higher-impact environments like construction sites. The interior has been built to handle heavy-duty tasks, such as hauling tools, equipment and building materials, but is spacious and comfortable enough to be a family vehicle.

On The Road

It’s not as big as the Suburban, but there’s no getting around the Tahoe Hybrid’s substantial size. If you’re not accustomed to driving a vehicle this large it will take some time to feel comfortable with its dimensions and how they affect road performance. For those familiar with a big SUV, the Tahoe Hybrid driving experience is rather ordinary.

Ordinary meaning that with a body-on-frame construction, independent front suspension and solid rear axle, the ride is slightly truck like. But only slightly. The Tahoe Hybrid feels planted during cornering and stable when cruising at 70 mph on the highway. In urban driving you need to know where the four corners of the vehicle are, but because you sit up high with a commanding view that is not difficult.

Driving a hybrid becomes a bit of game. From stop, a feather foot will maintain electric operation of the Tahoe for a couple of miles at the school-zone speed of 25 mph or so before the gas engine takes over. The cylinder deactivation also is a tool for increasing fuel economy. With a little practice, the big V8 can be coaxed into operating on four cylinders at around 40 mph, and can do so for several miles. On the highway, it’s not difficult to maintain four-cylinder operation at 70 mph.

The EPA rates both the two-wheel drive (2WD) and four-wheel drive (4WD) Tahoe Hybrid at 20 city/23 highway/21 combined. Since its introduction, staff at HybridCars.com has had several test drives. Driving conservatively, a 238 mile highway ride in a 2WD model yielded just over 21 miles per gallon, right on par with EPA estimates. A mixed 151-mile suburban drive – the type of traffic that 90 percent of Americans experience everyday – resulted in a surprising 24.8 miles per gallon, beating GM’s numbers by 15 percent. I clocked 427 mile in a 4WD Tahoe Hybrid, with about two-thirds on the Interstate. Staying at posted speed limits, I averaged 22.2 mpg. Certainly not Prius fuel mileage, but it beats the alternatives.

Economics

Because Chevy equips the Hybrid with a long, long list of standard features – like leather seating and navigation system – an apples-to-apples comparison to the various gas-powered Tahoe models has to be made with the top LTZ trim. And surprise, they are a few hundred dollars more with fuel economy ratings of 15 city/21 highway/17 combined for 2-WD and 4-WD models.

An apples-to-apples comparison to gas-powered competitors – Ford Expedition, Nissan Armada and Toyota Sequoia – is pretty much the same: comparably equipped models are in the $50,000 range and fuel economy is 30 to 40 percent less than the Tahoe Hybrid.
The 2013 model year Tahoe Hybrid is too new to calculate cost of ownership, but IntelliChoice gave an “Excellent” rating for the 2012 model. The automotive information provider estimated the five-year cost of ownership at $60,794, which is $5,204 less than similar vehicles.

Though the Tahoe Hybrid is not as efficient as the Chevy Volt or small cars (hybrid or non-hybrid), it is currently the greenest choice for those in genuine need of a full-size SUV. Bottom line: If you need to tote a bunch of kids and/or tow a trailer, this is the horse to ride.

What’s Next For The Tahoe Hybrid?

General Motors’ had planned an all-new full-size sport utility lineup including the Tahoe Hybrid for the 2013 model year, but put off production as it worked its way through bankruptcy.

A redesigned, re-engineered Tahoe line is expected to debut as a 2014 model at the 2013 North American International Auto Show in January or 2013 Chicago Auto Show in February, with production beginning next October.

The big question is, will a Tahoe Hybrid – or any of its sibling hybrid models – be included in the redesign? At this writing, it appears the answer is no.
We’ve been told that four sources told GM Inside News recently this was the case – but this news has not yet been confirmed by General Motors. The sources – believed to be reliable – said GM will discontinue development of its next-generation hybrid light trucks including the Chevrolet Tahoe, Silverado, and GMC Yukon and Sierra. There is a possibility the Cadillac Escalade Hybrid may be carried forward, but it appears they may all be canceled unless GM says otherwise.

Should the Tahoe Hybrid, and its corporate cousins, make an appearance as a 2014 model, it will continue to be built upon GM’s full-size truck platform, including a live rear axle for towing, and will not switch to a crossover design. Fuel economy gains will come from weight reduction and possibly, an all-new four-mode electrically variable transmission.

Prices are Manufacturer Suggested Retail Price (MSRP) at time of publication and do not include destination charges, taxes or licensing.

]]>http://www.hybridcars.com/chevy-tahoe-hybrid/feed/132Homegrown GM Electric Motors Will Power Future Hybridshttp://www.hybridcars.com/homegrown-gm-electric-motors-will-power-future-hybrids-26514/
http://www.hybridcars.com/homegrown-gm-electric-motors-will-power-future-hybrids-26514/#commentsTue, 26 Jan 2010 14:39:20 +0000http://127.0.0.1/wordpress12/?p=6516An electric traction motor (right) and stator (left) at the GM’s Powertrain Engineering Development Center. General Motors said on Tuesday it will set up a $246 million facility to build electric motors to power future hybrids. The first GM-designed and built electric motors would appear in 2013 in rear-wheel-drive two-mode hybrid vehicles. “In the future, […]

An electric traction motor (right) and stator (left) at the GM’s Powertrain Engineering Development Center.

General Motors said on Tuesday it will set up a $246 million facility to build electric motors to power future hybrids. The first GM-designed and built electric motors would appear in 2013 in rear-wheel-drive two-mode hybrid vehicles.

“In the future, electric motors might become as important to GM as engines are now,” said Tom Stephens, GM vice chairman, global product operations. “By designing and manufacturing electric motors in-house, we can more efficiently use energy from batteries as they evolve, potentially reducing cost and weight—two significant challenges facing batteries today.”

Stephens said the homegrown GM motors would also be more affordable and reliable, as well as easier to manufacture. GM’s investment in electric motor technology is supported by a $105-million grant awarded by the US Department of Energy in August.

More Two-Mode Hybrids on the Way

The announcement signals GM’s long-term commitment to its two-mode hybrid system, which so far has only been applied to large SUVs and pickup trucks, such as the Chevy Tahoe Hybrid and Chevy Silverado Hybrid. According to the company, new electric motors will enable GM to apply the two-mode hybrid system to smaller vehicles. The new motors would be smaller but offer more power density.

The first set of motors produced in-house will go to the two-mode hybrids, but GM is not ruling out making motors for the Chevy Volt and future pure electric vehicles. Currently, the company is building lithium ion battery packs for the Volt at a refurbished Michigan factory by assembling lithium ion cells supplied by South Korea’s LG Chem.

]]>http://www.hybridcars.com/homegrown-gm-electric-motors-will-power-future-hybrids-26514/feed/3World’s First Hybrid SUV Stretch Limohttp://www.hybridcars.com/worlds-first-hybrid-suv-stretch-limo-24936/
http://www.hybridcars.com/worlds-first-hybrid-suv-stretch-limo-24936/#commentsMon, 08 Sep 2008 02:26:19 +0000http://127.0.0.1/wordpress12/?p=3552Photo: Michael Coates, HybridCars.com. All rights reserved. It’s not the first hybrid stretch limousine, because a Canadian firm converted a Prius into a 10-seater last year. But it does appear to be the first stretch limo built from the body of a hybrid SUV, which would make it the world’s largest hybrid gas-electric vehicle—if it […]

It’s not the first hybrid stretch limousine, because a Canadian firm converted a Prius into a 10-seater last year. But it does appear to be the first stretch limo built from the body of a hybrid SUV, which would make it the world’s largest hybrid gas-electric vehicle—if it weren’t for hybrid buses and locomotives.

LimeLite CoachWorks of Santa Clara, Calif.—which builds a variety of stretch limos from Hummers and Escalades to Mini Coopers and Jaguar XFs—recently added more than 13 feet to a Chevrolet Tahoe Hybrid. LimeLite Business Development Representative Mike Williams told HybridCars.com that it’s the first hybrid limo off the line for the company, and was sold before it was finished being built. Zbest Limos of Baltimore, Md. will soon put the vehicle into service.

Williams noted that limo services historically have not paid much attention to fuel economy, but rising gas prices have given them new interest in the savings offered by hybrids. The company believes that using the Tahoe hybrid can yield up to 80 percent fuel savings compared to a comparable non-hybrid model.

When parked, all of the electronics in the Chevy Tahoe Hybrid limo run off the battery while traditional limos need to run the gas engine to power toys such as flat-screen TVs, Karaoke machines, full-service wet bars, and multi-color neon lighting. In the company’s first conversion, the usual purple neon lights were switched to green.

LimeLite has more hybrids on the way. Shop foreman Miguel De la Vega said the stretch of 160 inches in the first Tahoe was conservative—they now feel they can go to a more extreme 220-inch stretch. The company had no problems dealing with the high-voltage hybrid system, though De la Vega said he was “very careful.” All of the Tahoe’s hybrid system remains intact. In a standard limo, they would have added an additional battery and a beefed-up alternator.

Phil Restivo, president and CEO of LimeLite, told HybridCars.com that the hybrid limo business is just beginning. “The hybrid Escalade is coming in October,” he said. Since the standard Escalade is one of LimeLite’s big sellers, he thinks the hybrid version will also be popular.

]]>When the 2008 Chevrolet Tahoe Two-Mode Hybrid was named ‘Green Car of the Year’ by Green Car Journal last November, a lot of folks scratched their heads. Sure, the super-sized hybrid boasts relative benefits over comparably sized gas-powered SUVs, but is that enough to regard the Tahoe Hybrid as eco-friendly? The official EPA fuel economy ratings are 21 in the city and 22 on the highway, which represents a 30 percent increase in overall economy, and a 50 percent improvement in city driving.

We had an opportunity to drive the Tahoe Hybrid over the last few days, and to conduct two separate real world mileage loops in order to determine the vehicle’s fuel economy. The first was a highway drive from Cape May, New Jersey to Falls Church, Virginia. The 238-mile stretch ate through a little more than three-eighths of the 24.5 gallon gas tank, and yielded just over 21 miles per gallon, right on par with EPA estimates. Driving style was on the conservative side, as the vehicle stayed in the right hand lane for most of the road trip.

The second drive loop was comprised of mixed suburban driving in and around the Baltimore metropolitan area. Here, we tested the Tahoe hybrid in the type of traffic that 90 percent of Americans experience everyday. The result was surprising. The 151-mile drive test gave us 24.8 miles per gallon, beating GM’s numbers by 15 percent. Again, driving style was very conservative.

The Chevrolet Tahoe Hybrid, powered by its 6-liter V-8 gas engine in conjunction with electric motors, surpassed expectations for efficiency. For those who cannot live without a large vehicle, the Tahoe delivers the promised fuel economy. But the question still lurks: Is that enough to call it a green car, much less the “Green Car of the Year?”

]]>Carmakers spend big bucks to establish their brands as leaders in the race toward greater fuel efficiency and reduced emissions. Yet, many of the eco-friendly and high-tech innovations in our vehicles begin in the R&D departments of large auto suppliers—the companies that supply components and systems to automobile manufacturers. For example, you might know Continental Automotive Systems as a maker of tires, but you probably don’t know its role in the development of next-generation hybrids, diesels, lithium batteries, stability control, and wireless connectivity technologies for automobiles. We spoke with Bill Kozyra, president and CEO, Continental Automotive Systems North America, about what he sees as the three largest trends in automotive technology: sustainability, safety and connectivity.

What’s your projection for the growth of the hybrid car market?

I’m very optimistic that hybrids will continue to grow in this country. Where we’ll be in five or ten years from now, I can’t give you a percentage, but I can tell you that the current market—2.6 percent of new car sales—is going to grow every year.

We’re spending tens of millions of dollars investing in these fields, from an engineering development standpoint. We’re confident that our customers [the car companies] will be able to design in our hybrid systems, because what’s ultimately going to drive positive change is the cost side. Unless OEMs adopt consistent platforms across multiple car and truck lines, and we can be disciplined and offer that to multiple customers, it’ll never achieve economies of scale that are necessary for that technology to be fully exploited.

Continental is well positioned to support that growth with technology that we’ve developed, including for example with the lithium ion battery technology that we’re developing for General Motors for the Chevy Volt. We’re General Motors’s partners on development of lithium ion. You’ll see lithium ion batteries in production here at the end of next year, and the development is going quite well.

When you say ‘in production,’ you mean the batteries and the battery systems will be in production. But will they be placed in a production vehicle?

Absolutely.

By the end of next year?

Yeah. Specifically in the Chevrolet Volt in late 2009.

What’s your response to critics who say there are too many issues related to safety, cost, and battery life for lithium ion automobile batteries?

We’re dealing with all those issues and have been for some years now. We believe that, along with our development partners like General Motors, we have found solutions to deal with those issues, and are quite optimistic about the expanded use of lithium ion as a great alternative power source for these vehicles.

Where does conventional technology fit in, for example, low-resistance tires?

That’s all part of the equation. When we look at the total range of Continental production, we do everything from low-resistance tires to lightweight solutions in many areas, all of which go to improve fuel economy and reduce carbon dioxide emissions. In fact, we sat down six months ago, and took all the existing Continental technologies that are available for production today, and said if you were to implement all of them ready to go in the automotive industry, we could reduce carbon dioxide emissions by some 30 to 40 percent.

Meaning, a 30 to 40 percent improvement in fuel economy.

Right. On top of that, you can add new developments. You are going to see an explosion of improvements in efficiency in vehicles, including traditional technologies such as direct gasoline injection, turbochargers, double-clutch transmission technologies that we have in production, all the way to low-resistance tires. You add all that up, and you get a significant gain.

Yet, they each come with costs.

They don’t necessarily cost anything, but they need to be designed in. The low-rolling resistance tires have to be market competitive, so there may initially be some cost associated with some of the designs. In the long-term, that won’t necessarily come with a premium.

What kind of cars do you think we’ll be driving in 2030?

In 2030, you’ll have a lot more technologies on the road including the one we demonstrated in California [at the 2007 DARPA Challenge] with our autonomously driven vehicle. This is a vehicle that drives itself. It’s a Chevy Tahoe. It still had all the attributes of a full-size SUV, but it also had the capability of driving itself. This vehicle actually had its own eyes and ears and senses to be able to navigate an urban setting with other cars on the road and be able to do that in a very safe and efficient way.

It’s a demonstration of us being able to bring all three emerging technologies together: safety, sustainability, and connectivity. You’re going to see developments on sustainability go concurrent with a continued focus on safety, which has been the focus of the industry in the last decade or so. Technologies like electronic stability control. Now coming on strong are lane detection warning and blind-spot detection, and rear-end collision avoidance. You’ll see these technologies in the next couple of years, just exploding in the industry. That will compliment everything we are doing on the power train side and from a sustainability standpoint.

To the average driver out there, self-driving cars seem pretty futuristic. Aren’t there serious technical challenges on the sustainability and the connectivity front?

Sure, there are challenges. But when you look at the rapid pace of evolution in those areas, it’s phenomenal. Just in the last few years, advances in camera technology, in the image processing software that’s available to know the difference between a line in the road and a Coca-Cola can sitting in front of the car. The radar system might pick it up as an obstacle, but the camera knows, with the fusion of the sensors together, that it’s a Coca-Cola can. You certainly wouldn’t want the full brake applied.

These are the things that are advancing very quickly now, to be able to bring in more safety and sustainability into the car.

The challenge in presenting these ideas to the public is the idea of how far away we still are.

It’s just like any technology evolution. How many cars today do not have airbags, for example? Very few. Certainly all of them have seat belts. Our vision in five to seven years is that all of them will have electronic stability control, which is the single biggest life-saving technology known to man, next to seat belts.

Fifteen years from now, the vehicle that you and I will be able to enjoy will be far more sophisticated and efficient than the vehicle we can buy today. And I think that today’s vehicles are pretty great, by the way. They’re not as great as if we had a blank check book, and economies are always a factor, but rapid development in hardware technology and the ability to enhance performance is significant each and every year.

What do you drive today?

I drive a Cadillac Escalade ESV. I compromise on the fuel efficiency, but that’s the only thing that I give up with that car. I enjoy parking assist, wireless hands-free cell phone capability, satellite radio to listen to customized music, and all the capability of stability control. And I’m driving in a vehicle that I’m comfortable in. I’m a very happen American consumer and I enjoy, for my lifestyle, driving a large vehicle. The only thing I’m compromising is fuel efficiency, but I know the next generation to come will be significantly more efficient and significantly safer.

]]>Dan Neil, the Pulitzer-Prize winning auto journalist of the Los Angeles Times, says the Chevrolet Tahoe Hybrid deserves praise. “For sheer execution, you can do nothing but throw rose petals at the thing.” But he also poses a long list of questions about GM’s 6.0-liter V8 hybrid, which he calls, “a fantastically fuel-efficient vehicle that’s still a gas hog.”

The EPA estimated fuel economy for the Tahoe Hybrid is 21 miles per gallon in the city and 22 mpg highway. That represents about a 50% improvement of in-city fuel economy over the non-hybrid Tahoe.

Mr. Neil sees a lot of good in the Chevy Tahoe Hybrid:

The Tahoe can tow 6,200 pounds, which is “a tonnage that would fatally herniate a Toyota Highlander Hybrid.”

The smooth transitions from gas, to electric, and back, is “a astonishing [in its] seamlessness, the absence of shudder or second-order vibrations.”

The hybrid’s improved aerodynamic efficiency: “A slippery 0.34 Cd, compared to 0.39 Cd for the standard Tahoe. Not bad for a vehicle that looks like a refugee from the shipping yard at Long Beach.”

But for all this praise, Mr. Neil asks a number of bigger and tougher questions, not just aimed at GM engineers and marketeers, but the general public:

Shouldn’t the aerodynamic improvements be applied to the standard-issue Tahoe?

Do the super-low-volume sales targets (considering the $8,000 “hybrid premium”), do more for GM’s corporate image than its corporate average fuel economy?

Are critics being too harsh on GM?

Mr. Neil wonders, “Could it be we’re being cynical about a good-faith effort?”. He then answers his own question: “What really needs to be re-engineered, of course, is the consumer, who opts for these big, heavy-duty vehicles for personal transportation and light loading when smaller, lighter vehicles will do.”